feat: add pomodoro timer frontend with session management

chore: add blazor-component skill with CSS isolation rules

style: use param tags for record XML docs in pomodoro endpoints

docs: update auth spec with route protection and RedirectToAuth

feat: add global authorization with redirect to login page

docs: update auth spec and endpoint skill for RequireUserId policy

refactor: replace UserIdRequired pre-processor with security policy

test: add unit tests for pomodoro session endpoints

refactor: move PomodoroSettings to Features/Pomodoros/Settings

feat: add pomodoro session API endpoints

refactor: extract userId validation into FastEndpoints pre-processor

docs: add pomodoro timer implementation plan

docs: add pomodoro timer design document

docs: add layout module spec and update CLAUDE.md with theme infrastructure

feat: add bottom nav bar, stub pages and replace Home with TimerPage

feat: implement MainLayout with sidebar, appbar and theme switching

feat: add ThemeService for dark mode and drawer state persistence

docs: add main layout implementation plan

docs: add main layout design document